For a more enjoyable game of golf and to lower one's score, one has to hit the golf ball exactly with the face of a club, such as a driver, wood, iron, etc. To do so, it is important to establish an always consistent swing posture.
A golf swing performed as a rhythmical action not only enables a stable posture but also results in a stable trajectory of the golf ball and driving distance when an exact impact is achieved with each club. A golf swing may be divided into roughly seven steps, including the address, backswing, backswing apex (backswing top), downswing, impact, follow-through, finish, etc.
Korean Registered Patent No. 10-0982482 was provided for stable swing practice. The swing practice bat of the above registered patent lets the user know when the bat has reached the backswing apex point and the finish point by means of a sound made as a notifying ball impacts an alarm tube. In an indoor driving range, etc., the impact noise is not easily heard due to the noise made by other users practicing, etc. In making a golf swing, which requires concentration, this impact noise may disrupt the user's own swing practice. Also, the user has to burden the cost of buying a separate practice bat, and there is a lack of realism as the user has to practice swings with a practice bat that is different from a golf club.
When practicing golf swings, the address (posture) is important. For a user to check whether or not a normal address is being made, the user checks the so-called lie angle. Generally, the lie angle refers to the rear-side angle formed between the shaft of the golf club and the ground surface during the address. Generally, when a wedge is used, which has a shaft of a shorter length, the lie angle is greater, and conversely when a driver is used, the lie angle is smaller. Also, considering a specific golf club, a lie angle that is greater than normal (for example, when the distance between the golf ball and the tip of the foot is farther than normal) causes the heel portion of the golf club to be raised up from the ground surface. A lie angle that is smaller than normal (for example, when the distance between the golf ball and the tip of the foot is closer than normal) causes the toe portion of the golf club to be raised up from the ground surface. When the heel portion is raised up, the golf ball flies more to the right from the intended target direction. An effect comparable to a slice or a fade is obtained. When the toe portion is raised up, the golf ball would fly more to the left from the intended target direction. An effect comparable to a hook or a draw is obtained. It may thus be said that it is important for a user to check the lie angle during the address based on his/her own posture.
Also, there is a need for a device that can measure swing speed during use of the practice bat, so as to virtually estimate the driving distance for each corresponding club, and enable the user to check whether or not the strength, etc., of the shaft of the golf club owned by the user is adequate for the swing speed, etc., for suitable club fitting.
Furthermore, there is a need for a device that can measure the swing speed and predict the distance as converted for each club, to allow the user to maintain a consistent swing tempo. Also needed is a device that allows the user to check the swing trajectory, i.e. the swing plane, during swing practice and thus maintain a consistent swing plane.